Preheat your oven to 325?.
Drizzle the olive oil into the bottom of the pan and place chicken breasts in the pan. Don’t overcrowd the chicken and make sure that each breast is placed flatly in the pan.
Coat the chicken breasts with the garlic powder and place the chopped onion into the pan.
Place the lid on your Dutch oven or braiser and put it into your preheated oven on the middle rack. You’ll cook the chicken for about an hour. Turn the chicken about 30 minutes in to prevent it from drying out.
Carefully remove the Dutch oven from the oven and when cool enough, shred the chicken using two forks for a meat shredder. You can shred the chicken inside the pan or take it out and shred it on a cutting board and place it back inside the pan when done.
Mix the shredded chicken thoroughly with the juices. At this point, you can add in the optional barbecue sauce, chicken stock, or any seasonings you’d like.